Battery-powered portable electronic devices such as mobile form factor devices are useful only as long as the battery has enough charge. Device features that are active or running, however, may affect how long the battery stays charged; some features may consume more battery power than others may. If battery-consuming features are enabled, the battery may need to be recharged more frequently. If, however, such features are not enabled a user may lose a benefit of the portable electronic device. To avoid complete loss of such a benefit, the user may resort to frequent enabling and disabling of a particular device feature.
The display of a portable electronic device is a feature that is a big consumer of battery charge. This may be exacerbated if the device display is relatively large compared to the device size as a whole. Since a user typically interacts with the portable electronic device through an interface displayed on the display screen, the user cannot simply turn off the display and still use other features of the portable electronic device. Thus, to save battery, the user may turn the display completely off or dim the light for the entire display. But to use the portable electronic device, it may be necessary to turn the display back on, increase the intensity of the display light, or both.